The INSTALLATION.md file doesn't tell you to install typescript

[palisadoes]

Is your feature request related to a problem? Please describe.

1. The INSTALLATION.md file doesn't tell you how to install typescript
2. This is an obvious omission and must be fixed

Describe the solution you'd like

1. Update the INSTALLATION.md file to explain how to install typescript in the correct order after installing npm
2. Make this a separate section in the procedure
3. Ensure that the table of contents is correctly updated

Potential internship candidates
Please read this if you are planning to apply for a Palisadoes Foundation internship PalisadoesFoundation/talawa#359

[techmannih]

Hello @palisadoes ,
I want to work on this issue please assign me

[Cioppolo14]

@techmannih I just assigned you another issue, so now you have two. Our policy is to assign no more than two issues to each contributor across all repositories. This way everyone gets a chance to participate in the projects. We sometimes give exceptions for more urgent cases and sometimes we lose track, but the policy stands. You have reached your limit, please wait until your existing issues are closed before requesting more issues. You could unassign yourself from one of the other issues too.

[techmannih]

Okay @Cioppolo14
Thanks

[Veer0x1]

@Cioppolo14 can you assign me?

[Veer0x1]

Why hasn't this issue got closed, when the PR got merged?

[Cioppolo14]

@Veer0x1 I am looking into it.